The most painful wasp sting in the world explained

By Emily Osterloff

First published 7 September 2017

Armed with one of the most painful stings on the planet, tarantula hawks are a spider's worst nightmare.

A fear of insects is common among humans, but for some spiders, stings really can be a matter of life or death. One wasp in particular makes even the biggest, hairiest spider run away in terror: the tarantula hawk.

Dr Gavin Broad, wasp expert at the Museum, uncovers the eccentricities of this small but sinister creature.

Bird or spider?

Despite their name, tarantula hawks (Pepsis genus) are actually a species of spider wasp.

The largest species of tarantula hawk, Pepsis heros, will be going on display at the Museum in summer 2017

Reaching up to 11 centimetres in length, these insects lead solitary lives and their 133 known species are found across South and Central America and in the southern United States.

They are named after their habit of hunting tarantulas, which are often considerably larger than themselves - but these wasps do so with little risk to their own lives.

If stung, just scream

For humans and other vertebrates, the tarantula hawk has one of the most painful stings on the planet.

American entomologist Justin Schmidt created the sting pain index, with the help of variably willing or unwitting test subjects. He once described the tarantula hawk's sting as 'instantaneous, electrifying and totally debilitating'.

The tarantula hawk has been awarded second place on the Schmidt sting pain index, beaten only by the South American bullet ant (Paraponera clavata).

The pain from a bullet ant sting lasts up to 24 hours, whereas that of a wasp usually only aggravates the unlucky victim for five minutes.

Schmidt has also in the past suggested that when stung, the only response is to 'lay down and scream'.

Witness the swarm

Visitors to the Museum can see the largest species of tarantula hawk, Pepsis heros, from southeastern Peru in the recently redeveloped Hintze Hall. The specimen is part of an impressive new display of swarming insects.